feat(users): add pagination to users endpoint

models/content.js

@@ -4,6 +4,7 @@ import { v4 as uuidV4 } from 'uuid';
 import { ForbiddenError, ValidationError } from 'errors';
 import database from 'infra/database.js';
 import balance from 'models/balance.js';
+import pagination from 'models/pagination.js';
 import prestige from 'models/prestige';
 import user from 'models/user.js';
 import validator from 'models/validator.js';
@@ -218,7 +219,7 @@ async function findWithStrategy(options = {}) {
 
     options.order = 'published_at DESC';
     results.rows = await findAll(options);
-    options.totalRows = results.rows[0]?.total_rows;
+    options.total_rows = results.rows[0]?.total_rows;
     results.pagination = await getPagination(options);
 
     return results;
@@ -229,7 +230,7 @@ async function findWithStrategy(options = {}) {
 
     options.order = 'published_at ASC';
     results.rows = await findAll(options);
-    options.totalRows = results.rows[0]?.total_rows;
+    options.total_rows = results.rows[0]?.total_rows;
     results.pagination = await getPagination(options);
 
     return results;
@@ -252,34 +253,17 @@ async function findWithStrategy(options = {}) {
       results.rows = rankContentListByRelevance(contentList);
     }
 
-    values.totalRows = results.rows[0]?.total_rows;
+    values.total_rows = results.rows[0]?.total_rows;
     results.pagination = await getPagination(values, options);
 
     return results;
   }
 }
 
-async function getPagination(values, options = {}) {
+async function getPagination(values, options) {
   values.count = true;
-
-  const totalRows = values.totalRows ?? (await findAll(values, options))[0]?.total_rows ?? 0;
-  const perPage = values.per_page;
-  const firstPage = 1;
-  const lastPage = Math.ceil(totalRows / values.per_page);
-  const nextPage = values.page >= lastPage ? null : values.page + 1;
-  const previousPage = values.page <= 1 ? null : values.page > lastPage ? lastPage : values.page - 1;
-  const strategy = values.strategy;
-
-  return {
-    currentPage: values.page,
-    totalRows: totalRows,
-    perPage: perPage,
-    firstPage: firstPage,
-    nextPage: nextPage,
-    previousPage: previousPage,
-    lastPage: lastPage,
-    strategy: strategy,
-  };
+  values.total_rows = values.total_rows ?? (await findAll(values, options))[0]?.total_rows ?? 0;
+  return pagination.get(values);
 }
 
 async function create(postedContent, options = {}) {

models/controller.js

@@ -125,22 +125,27 @@ function logRequest(request, response, next) {
 
 function injectPaginationHeaders(pagination, endpoint, response) {
   const links = [];
-  const baseUrl = `${webserver.host}${endpoint}?strategy=${pagination.strategy}`;
+  const baseUrl = `${webserver.host}${endpoint}`;
 
-  if (pagination.firstPage) {
-    links.push(`<${baseUrl}&page=${pagination.firstPage}&per_page=${pagination.perPage}>; rel="first"`);
-  }
-
-  if (pagination.previousPage) {
-    links.push(`<${baseUrl}&page=${pagination.previousPage}&per_page=${pagination.perPage}>; rel="prev"`);
-  }
+  const searchParams = new URLSearchParams();
 
-  if (pagination.nextPage) {
-    links.push(`<${baseUrl}&page=${pagination.nextPage}&per_page=${pagination.perPage}>; rel="next"`);
+  if (pagination.strategy) {
+    searchParams.set('strategy', pagination.strategy);
   }
 
-  if (pagination.lastPage) {
-    links.push(`<${baseUrl}&page=${pagination.lastPage}&per_page=${pagination.perPage}>; rel="last"`);
+  const pages = [
+    { page: pagination.firstPage, rel: 'first' },
+    { page: pagination.previousPage, rel: 'prev' },
+    { page: pagination.nextPage, rel: 'next' },
+    { page: pagination.lastPage, rel: 'last' },
+  ];
+
+  for (const { page, rel } of pages) {
+    if (page) {
+      searchParams.set('page', page);
+      searchParams.set('per_page', pagination.perPage);
+      links.push(`<${baseUrl}?${searchParams.toString()}>; rel="${rel}"`);
+    }
   }
 
   const linkHeaderString = links.join(', ');

models/pagination.js

@@ -0,0 +1,26 @@
+async function get({ total_rows, page, per_page, strategy }) {
+  const firstPage = 1;
+  const lastPage = Math.ceil(total_rows / per_page);
+  const nextPage = page >= lastPage ? null : page + 1;
+  const previousPage = page <= 1 ? null : page > lastPage ? lastPage : page - 1;
+
+  const pagination = {
+    currentPage: page,
+    totalRows: total_rows,
+    perPage: per_page,
+    firstPage: firstPage,
+    nextPage: nextPage,
+    previousPage: previousPage,
+    lastPage: lastPage,
+  };
+
+  if (strategy) {
+    pagination.strategy = strategy;
+  }
+
+  return pagination;
+}
+
+export default Object.freeze({
+  get,
+});

models/user.js

@@ -3,6 +3,7 @@ import database from 'infra/database.js';
 import authentication from 'models/authentication.js';
 import balance from 'models/balance.js';
 import emailConfirmation from 'models/email-confirmation.js';
+import pagination from 'models/pagination.js';
 import validator from 'models/validator.js';
 
 async function findAll() {
@@ -25,6 +26,55 @@ async function findAll() {
   return results.rows;
 }
 
+async function findAllWithPagination(values) {
+  const offset = (values.page - 1) * values.per_page;
+
+  const query = {
+    text: `
+      WITH user_window AS (
+        SELECT
+          COUNT(*) OVER()::INTEGER as total_rows,
+          id
+        FROM users
+        ORDER BY updated_at DESC
+        LIMIT $1 OFFSET $2
+      )
+
+      SELECT
+        *
+      FROM
+        users
+      INNER JOIN
+        user_window ON users.id = user_window.id
+      CROSS JOIN LATERAL (
+        SELECT
+          get_user_current_tabcoins(users.id) as tabcoins,
+          get_user_current_tabcash(users.id) as tabcash
+      ) as balance
+      ORDER BY updated_at DESC
+    `,
+    values: [values.limit || values.per_page, offset],
+  };
+
+  const queryResults = await database.query(query);
+
+  const results = {
+    rows: queryResults.rows,
+  };
+
+  values.total_rows = results.rows[0]?.total_rows ?? (await countTotalRows());
+
+  results.pagination = await pagination.get(values);
+
+  return results;
+}
+
+async function countTotalRows() {
+  const countQuery = `SELECT COUNT(*) OVER()::INTEGER as total_rows FROM users`;
+  const countResult = await database.query(countQuery);
+  return countResult.rows[0].total_rows;
+}
+
 async function findOneByUsername(username, options = {}) {
   const baseQuery = `
       WITH user_found AS (
@@ -446,6 +496,7 @@ async function updateRewardedAt(userId, options) {
 export default Object.freeze({
   create,
   findAll,
+  findAllWithPagination,
   findOneByUsername,
   findOneByEmail,
   findOneById,

pages/api/v1/users/index.public.js

@@ -19,21 +19,39 @@ export default nextConnect({
   .use(authentication.injectAnonymousOrUser)
   .use(controller.logRequest)
   .use(cacheControl.noCache)
-  .get(authorization.canRequest('read:user:list'), getHandler)
+  .get(getValidationHandler, authorization.canRequest('read:user:list'), getHandler)
   .post(
     postValidationHandler,
     authorization.canRequest('create:user'),
     firewall.canRequest('create:user'),
     postHandler,
   );
 
+function getValidationHandler(request, response, next) {
+  const cleanValues = validator(request.query, {
+    page: 'optional',
+    per_page: 'optional',
+  });
+
+  request.query = cleanValues;
+
+  next();
+}
+
 async function getHandler(request, response) {
   const userTryingToList = request.context.user;
 
-  const userList = await user.findAll();
+  const results = await user.findAllWithPagination({
+    page: request.query.page,
+    per_page: request.query.per_page,
+  });
+
+  const userList = results.rows;
 
   const secureOutputValues = authorization.filterOutput(userTryingToList, 'read:user:list', userList);
 
+  controller.injectPaginationHeaders(results.pagination, '/api/v1/users', response);
+
   return response.status(200).json(secureOutputValues);
 }